Cast chains



Feb. 18, 1969 c. D. MCLEISH 3,427,801

CAST CHAINS Filed Aug. 11, 1964 32 INVE/V r00. Car p. yfzcow @MgWATTORNEY.

United States Patent 3,427,801 CAST 'CHAINS Charles D. McLeish,Waterloo, Ontario, Canada, assignor to Indiana General Corporation,Chicago, Ill. Filed Aug. 11, 1964, Ser. No. 388,834 U.S. Cl. 59-1 Int.Cl. B21] 17/00; B2211 25/02 4 Claims ABSTRACT OF THE DISCLOSURE Thisinvention relates to cast metal chains and more particularly to a novelchain and the method or process of making same.

In the industry of making cement, lime and similar related products,large rotating kilns are used through which the material flows underrelatively high temperatures. In order to keep the material moving, tobreak up clumps, to keep the material agitated and to transfer heat tothe material the inside of the kiln is laced with lengths of chain whichhang down from the upper part of the kiln and stack up on the lowersides and bottom of the kiln. As the kiln rotates the links of thechains constantly bump against each other and agitate the material andduring part of the rotation cycle absorb heat and during the remainderof the cycle transfer heat. The agitation causes the links of the chainsto be subjected to extreme wear. This is caused by the constant abradingaction of one link against another, of the links against the sides ofthe kiln and of the presence of the material being treated which, beingpowdery in nature, is abrasive to the constantly moving chains.

In the past the links of the kiln chains have generally been made ofwrought alloys including stainless steel and carbon steels. Even withthese expensive alloys and steels the replacement rate of chain links isfantastic. The links wear both on the inside and outside and erode fromthe effects of the constant high temperature so that they have to bereplaced frequently. The kiln must be taken out of service, cooled downand the chains replaced at great expense.

It is therefore a principal object of this invention to provide animproved chain for use in kilns that will have higher resistance to wearand better temperature characteristics.

It is another object of this invention to provide an improved method ofmaking kiln chain links that will produce links for kiln chains ofunusual creep strength.

It is still another object of this invention to provide an improvedmethod of making kiln chain by casting and welding using a differentbasic material whereby better chains are produced at a cheaper cost.

And yet another object of this invention is to provide a novel method ofcasting the chain links thereby facilitating assembly of the chains foruse.

These and other novel features of the invention will be best understoodfrom the following description when taken together with the accompanyingdrawings, in which certain embodiments of the invention are disclosed,and in which the separate parts are designated by suitable referencecharacters in each of the views, and in which:

FIGURE 1 is a plan view illustrating a pattern plate for casting linksfor my improved kiln chain;

lot:

FIGURE 2 is a plan view of several links of chain such as cast in thepattern of FIGURE 1 in partially assembled relationship;

FIGURE 3 is a view of several links assembled in a ig with one link inposition ready for welding;

FIGURE 4 is a cross-sectional view taken on the line 4-4 of FIGURE 2illustrating one of several advantageous cross-sections for kiln chains.

My invention deals generally with the casting of solid links and splitlinks which can then be joined together in such a way as to produce achain of improved wear and heat resistant characteristics.

In order to simplify illustration of the invention, somewhat schematicviews are employed showing in the least amount of detail the essentialfeatures to be included within my invention.

Referring to the drawings wherein similar reference numerals refer tosimilar parts throughout the several views, 10 represents the lower halfof a pattern plate or die box which is adapted to have sand or the like12 tamped therein with the imprint of a pattern 14 embedded into thesand in the form of two solid links or rings 16 and 18 and two splitlinks or rings 20 and 22 all connected by sprews 24 to a gate 26. Anupper half 28 of the pattern plate contains a mirror image of theimprint of a pattern 14 such that when the upper half 28 is placed overthe lower half 10 a completed mold is formed ready for casting. It is tobe understood that the mold can be made in many different and other wellknown ways such as by shell molding, and the like.

Casting alloys are then poured into the mold in the usual mannerwhereupon a casting resembling the impression of the pattern 14 ofFIGURE 1 is produced. The sprews and risers are knocked off the links16, 18, 20 and 22 whereupon said links are cleaned and otherwiseprepared for assembling. Two of the solid rings or links 16 and 18 areassemble-d with one split link 20 (or 22) by passing the solid ringsthrough the opening 30 in the split link 20. The split link 20 is thenplaced in a jig 34 which has a pair of reciprocally spaced jaws 36 and38. The jaws 36 and 38 are aligned with diametrically opposite sides ofthe split link 20 with the opening 30 somewhat centrally spaced betweenthe jaws.

The jig is activated and the jaws force the sides of the split linktogether until the opening 30' is closed. A welding step is thenpreformed on the ends of the link forming the opening 30 whereupon thesplit link 20 is welded at 32 into a solid link. The procedure isrepeated many times to produce a kiln chain.

The newly formed chain being of alloy cast material is much moreresistant to wear and heat and especially to the abrasive type wearoccasioned by the constant rubbing and banging of the chains one againstthe other with the interposed material being processed in the kiln.

Chains made out of wrought or rolled stock are not sufficiently wearresistant to stand the heat and wear created during long and constantuse in a kiln.

Cast alloys have high creep strength which is not only necessary butalso is essential to successful use of chains for kilns. Creep strengthis defined as the constant nominal stress that will cause a specificquantity of strain or creep rate at constant temperature in a giventime. By modifications of compositions superior creep strength can begiven to casting alloys over wrought alloys.

The cast links of my chain can be made in various cross-sectionconfigurations, to give maximum heat radiation surface area with minimumof weight, thus reducing fuel costs and keeping the weight economical.The shape of the links insures greater chain flexibility, reduces chainknotting, increases the scraping action in the kiln and is self-cleaningand prevents the formation of mud clumps.

In FIGURE 4 one cross-section that has been found to be very useful andhas contributed to an improved chain is illustrated. The cross-sectionis essentially a figure 8 such that a greater surface area is exposed insuch a way as to improve particularly the heat transfer characteristics.The greater heat transfer of the chains the more efficient the kilnoperation, all of which is true with my improved cast chains.

The greater wear resistance of the cast alloy chains effects manysavings. The initial chains are cheaper to produce, and since they lastlonger they save replacement costs and reduce downtime for the kiln.Each time a kiln is taken out of service to repair or replace kilnchains it necessitates flushing the kiln, cooling it down, working onthe chains and then refiring and reheating before it is returned toservice, all of which takes time and money.

By the improved chain and method of making same, it is possible toproduce a better kiln chain, cheaper and more efficiently.

Having thus described my invention, what I claim is:

1. A method of forming a chain which comprises casting closed rings andopen rings from an alloy, said alloy being of a composition havingsubstantial creep strength and high wear resistance, assembling twoclosed rings with each open ring by inserting the open end of the openring into the centers of the closed rings, forcing the ends of the openring together and welding said ends together to form another closed ringjoining the two cast closed rings.

2. A chain for use in rotating kilns comprising a pair of closed rings,an open ring joining said closed rings and having means for permanentlyclosing the opening in said open ring, all of said rings being formed bycasting an alloy into said rings, and said alloy having high creepstrength and high wear and heat resistant characteristics.

3. A chain for use in a rotating kiln comprising a plurality of linksconnected together and having every other link a solid closed linkjoined by an open link which has been permanently welded closed, all ofsaid links being formed by means of casting of an alloy said alloyhaving high creep strength and high wear resistant characteristics, andeach link having a cross-sectional shape such as to provide a relativelylarge exposed surface area so as to improve the heat transfercharacteristics of said chain.

4. A process of making a chain comprising the steps of preparing a mold,having open links and closed links, pouring into said mold a castingalloy having substantial creep strength and high heat and wearresistance characteristics, assembling an open link between every pairof closed links, welding the opening shut in each open link whereby acast chain is formed for use in a kiln or the like.

References Cited UNITED STATES PATENTS 354,732 12/1886 Penman 249-571,670,758 5/1928 Witherow 59-35 2,820,874 1/1958 Dunn 59-31 3,015,7161/1962 Pelkey 24957 3,135,504 6/1964 Chisler 263-33 3,176,3 7 4/1965Nelson 249-57 CHARLES W. LANHAM, Primary Examiner.

G. P. CROSBY, Assistant Examiner.

US. Cl. X.R.

